Method and apparatus for dielectric bonding of silicon wafer flow fields

Abstract

According to one embodiment of the invention a fuel cell can be configured so as to directly bond silicon substrate flow field plates directly to one another via a dielectric bond without allowing reactant gases to penetrate the flow field plates during operation of the fuel cell.

1 . An apparatus comprising: 
 a first silicon substrate flow field plate for use in a fuel cell and configured to prevent transmission of a first reactant gas through said first silicon substrate;    a second silicon substrate flow field plate for use in said fuel cell and configured to prevent transmission of a second reactant gas through said second silicon substrate;    a dielectric bonding material disposed between said first silicon substrate flow field plate and said second silicon substrate flow field plate.    
     
     
         2 . The apparatus as claimed in  claim 1  wherein said dielectric bonding material directly couples said first silicon substrate flow field plate with said second silicon substrate flow field plate.  
     
     
         3 . The apparatus as claimed in  claim 1  and further comprising a proton exchange membrane disposed between said first silicon substrate flow field plate and said second silicon substrate flow field plate.  
     
     
         4 . The apparatus as claimed in  claim 3  wherein said dielectric bonding material couples said first silicon substrate flow field plate with said second silicon substrate flow field plate without utilizing a gasket at the interfaces between said first and second silicon substrate flow field plates and said proton exchange membrane.  
     
     
         5 . The method as claimed in  claim 3  wherein said first silicon substrate flow field plate and said second silicon substrate flow field plate maintain compression of said proton exchange membrane via said dielectric bonding material without the assistance of a device configured to exert an external pressure directly against said first silicon substrate flow field plate and said second silicon substrate flow field plate.  
     
     
         6 . The apparatus as claimed in  claim 5  wherein said dielectric bonding material electrically insulates said first silicon substrate flow field plate from said second silicion substrate flow field plate.  
     
     
         7 . The apparatus as claimed in  claim 6  wherein said dielectric bonding material prevents leakage of a reactant gas between said first and second flow field plate.  
     
     
         8 . The apparatus as claimed in  claim 6  wherein said dielectric bonding material structurally separates said first silicon substrate flow field plate from said second silicon substrate flow field plate.  
     
     
         9 . The apparatus as claimed in  claim 1  wherein said dielectric bonding material forms a permanent bond and wherein said permanent bond is maintained in a corrosive operating environment.  
     
     
         10 . The apparatus as claimed in  claim 1  wherein said dielectric bonding material forms a permanent bond and wherein said permanent bond is maintained in an operating environment having an operating temperature between about 160 and about 200 degrees Celsius.  
     
     
         11 . The apparatus as claimed in  claim 3  wherein said proton exchange membrane comprises an electrolyte layer, a first gas diffusion layer, and a second gas diffusion layer.  
     
     
         12 . A method comprising: 
 providing a first silicon substrate flow field plate for use in a fuel cell and configured to prevent transmission of a first reactant gas through said first silicon substrate;    providing a second silicon substrate flow field plate for use in said fuel cell and configured to prevent transmission of a second reactant gas through said second silicon substrate;    disposing a dielectric bonding material between said first silicon substrate flow field plate and said second silicon substrate flow field plate.    
     
     
         13 . The method as claimed in  claim 12  and further comprising directly coupling said first silicon substrate flow field plate with said second silicon substrate flow field plate via said dielectric bonding material.  
     
     
         14 . The method as claimed in  claim 12  and further comprising disposing a proton exchange membrane between said first silicon substrate flow field plate and said second silicon substrate flow field plate.  
     
     
         15 . The method as claimed in  claim 14  and further comprising utilizing said dielectric bonding material to couple said first silicon substrate flow field plate with said second silicon substrate flow field plate while not utilizing a gasket at the interfaces between said first and second silicon substrate flow field plates and said proton exchange membrane.  
     
     
         16 . The method as claimed in  claim 14  and further comprising configuring said dielectric bonding material so as to form a dielectric bond that maintains compression of said proton exchange membrane between said first and second silicon substrate flow field plates without the assistance of a device configured to exert an external pressure directly against said first silicon substrate flow field plate and said second silicon substrate flow field plate.  
     
     
         17 . The method as claimed in  claim 16  and further comprising electrically insulating said first silicon substrate flow field plate from said second silicon substrate flow field plate.  
     
     
         18 . The method as claimed in  claim 17  and further comprising preventing leakage of a reactant gas between said first and second flow field plate via said dielectric bond.  
     
     
         19 . The method as claimed in  claim 17  and further comprising structurally separating said first silicon substrate flow field plate from said second silicon substrate flow field plate via said dielectric bond.  
     
     
         20 . The method as claimed in  claim 12  and further comprising forming a permanent bond via said dielectric bonding material and wherein said permanent bond is maintained in a corrosive operating environment.  
     
     
         21 . The method as claimed in  claim 12  and further comprising forming a permanent bond via said dielectric bonding material and wherein said permanent bond is maintained in an operating environment having an operating temperature between about 160 and about 200 degrees Celsius.  
     
     
         22 . The method as claimed in  claim 14  wherein said proton exchange membrane comprises an electrolyte layer, a first gas diffusion layer, and a second gas diffusion layer.